Input: adp5588-keys - unify common header defines

Unify adp5588-gpio and adp5588-keys common header defines (as per Andrew
Morton request). For consistency, move remaining defines and prefix
accordingly.

No functional changes.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>